Loans Receivable (Accretable yield and non-accretable discount activity of covered loans) (Details) (Acquired Loans In An F D I C Assisted Transaction [Member], USD $) In Thousands, unless otherwise specified	12 Months Ended
Dec. 31, 2014	Dec. 31, 2013	Dec. 31, 2012
Acquired Loans In An F D I C Assisted Transaction [Member]
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]
Balance at beginning of period	$ 162,959	$ 188,008	$ 188,822
Accretion Accretable	(88,969)	(91,769)	(85,376)
Transfer from (to) non-accretable discount	35,869	66,720	84,562
Balance at end of period	109,859	162,959	188,008
Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Non Accretable Discount Movement Schedule [Roll Forward]
Balance at beginning of period	129,477	237,555	412,170
Principal Losses	(31,198)	(41,358)	(90,053)
Transfer (to) from accretable yield	(35,869)	(66,720)	(84,562)
Balance at end of period	$ 62,410	$ 129,477	$ 237,555

Loans Receivable (Accretable yield and non-accretable discount activity of covered loans) (Details) (Acquired Loans In An F D I C Assisted Transaction [Member], USD $)
In Thousands, unless otherwise specified

12 Months Ended

Dec. 31, 2014

Dec. 31, 2013

Dec. 31, 2012

Acquired Loans In An F D I C Assisted Transaction [Member]

Certain Loans Acquired in Transfer Not Accounted for as Debt Securities, Accretable Yield Movement Schedule [Roll Forward]

Balance at beginning of period